I bought the Caldwell Matrix so I could use it for my AR and am quite happy with it, more so than my old LeadSled for informal use of both rifles and a pistol. I'm a hunter and a target plinker. That said for your starter purpose and a bit more money I think you'd be better off with the combo. https://www.walmart.com/ip/Caldwell...640-Rock-Front-Shooting-Rest-Padded-Rear-Filled-Canvas-Bag-Combo-Green/35650448
I haven't used it but the Solo doesn't look nearly solid enough.

 

I have and don't care for the lead sled unless you are shooting large caliber. These rests that have the rear arm to cradle the butt of the gun , for me interfere with me getting positioned for proper eye relief with a scoped rifle. Also by their very nature they are heavy to dampen the recoil. I mostly shoot 22 rim fires and varmint rifles so I don't need the recoil reduction. With that said , I do like the Caldwell Matrix also.

 

I have a Caldwell lead sled solo. The major benefit of the lead sled is ameliorating recoil. I use mine when I am testing loads in my 308. But, use a more traditional reset for my rimfires and 223.